In the most remote forests of Hawai‘i live
native species that most people never hear of, let alone see. In many cases
species are hidden not only from adventurous hikers, but also from scientists.
“A lot of these species were originally described, but then nobody has looked
at them for a hundred years,” says Chris Johns, a doctoral candidate at the
University of Florida who studies creatures that have been overlooked for the
better part of a century: micromoths.

Micromoths would be as easily missed in a
country garden as a remote jungle valley; the full-grown adults are
astonishingly small: “the size of an eyelash,” Johns says. “And when I say
eyelash, I mean eyelash. Certainly the length of an eyelash, and they’re maybe
two eyelashes thick.” As caterpillars, the grubs are so tiny they live within
the leaf. As they grow, they tunnel through the leaf, eating the tissue and
leaving behind tracks called “mines”—earning micromoth larvae the common name “leaf
miners.” Their mining patterns are sometimes unique to a species, so an
entomologist can tell exactly what’s burrowing inside without even seeing the
insect. Hawai‘i has its own special genus of micromoths, Philodoria, which is found nowhere else. Different Philodoria species are inextricably tied
to the specific plants they eat, with each moth species feeding exclusively on
one genus or even species of native Hawaiian plant.

Johns learned about Philodoria from his doctoral adviser Akito Kawahara, assistant
professor and curator at the University of Florida/Florida Museum of Natural
History’s McGuire Center for Lepidoptera and Biodiversity. “While he was in
Hawai‘i for his postdoc, he got attached to all sorts of different Hawaiian
insects,” Johns says of Kawahara, micromoths among them. “Not much had really
been done scientifically, which is the case with a lot of Hawaiian insects.”

Philodoria were first described by Lord
Thomas de Grey Walsingham, a British politician and amateur entomologist, in
1907. Otto H. Swezey, an entomologist with Hawai‘i’s sugar industry, developed
an affection for the little insects and added more species to Walsingham’s
preliminary collection. But from about the end of World War II until Kawahara
arrived in Hawai‘i, Philodoria were
essentially forgotten. No one knew how many species were still around. Eager to
re-examine the genus, Kawahara kept his eye out for a graduate student who
might be interested in Hawai‘i’s micromoths; he found that student in Johns.

The first time Johns and his team went in
search of Hawai‘i’s micromoths, he found a lot of fragmented populations and
several new species. “Since then we’ve been going back and slowly filling in
the picture of what’s there—what’s new, what was previously undiscovered, what
was once discovered and has now been extirpated or gone extinct.”

Of course, finding micromoths is no simple
feat, and while there is a certain romance to being out in the field in a place
as beautiful as Hawai‘i, “it’s a really tedious process,” says Johns. “We’re
going hours and hours and miles and miles into the forest to try to find these
things.” The first step is to find the plants that the caterpillars eat. The
scientists then check the leaves for a mine, and sometimes the caterpillar is
still inside. Sometimes it’s alive, sometimes dead, and “sometimes we don’t
find them at all,” says Johns. Adult moths are even harder to spot. “I’ve only
ever seen maybe thirty wild adult moths in my four years of doing the project.
They’re just so tiny. If they fly away and leave your two-foot vicinity, then
they’re lost in the forest. You just won’t ever find them again.”

Because Philodoria
live exclusively on rare native plants, Johns needs help to find his bugs.
Keahi Bustamante, who was working for the Plant Extinction Prevention Program
on Maui when Johns met him, has been an invaluable partner; extremely rare
native plants are his specialty. Johns asked for Bustamante’s help, and the two
became friends. When Johns is back in Florida for his studies, Bustamante hunts
caterpillars for him. To Bustamante, studying something even so tiny and
seemingly insignificant as Philodoria
represents an important contribution. “We’ve already lost so much of our native
forests,” he says, “and the little moths and insects, they’re a huge part of
what makes the forest eco-system work.”

Hidden in the leaves of the native shrub kolea,
for example, are the larvae of Philodoria
auromagnifica, whose adults are breathtaking up close. “They’ve got all
this silver and metallic color on their wings,” says Johns. “They’re
beautiful.” His favorite species, though, is the elusive P. molo-kaiensis, which lives exclusively on the endemic Lysimachia
shrub (kolokolo kuahiwi in Hawaiian) on Moloka‘i. “It’s such a beautiful moth,
and it’s found only on this one Lysimachia on Moloka‘i,” Johns says reverently.
“I just think it’s so cool that this organism is eking out its little existence
in the mountains there, unbeknownst to most people.”

In the room that houses Bishop Museum’s
entomology collection, Jim Boone lays out specimens of Philodoria from the museum’s vaults on a bench. As the museum’s
entomology collection manager, Boone has worked with Johns over the past few
years, giving him access to specimens collected a century ago for comparison
with those he’s found recently.

About two hundred unbelievably tiny moths are
pinned, with their wings ex-tended, to a small piece of foam atop a stack of
labels, each no more than a half inch long and a quarter-inch wide, describing
when, where and by whom the insect was collected. The labels accompanying the
older specimens—including the first ever collected—are handwritten in
implausibly small, neat cursive. “Back then they used fountain pens with India
ink,” Boone explains. Recent additions are easy to spot; their labels are
pristine white and printed from computer. “We now use 3.5 font size,” says
Boone. Small as they are, the labels dwarf the specimens they describe. “You
need a microscope to really see what they look like,” Boone says as he sets up
a dissecting scope, places a minuscule brown moth underneath its lens and calls
me over.

Looking in, I gasp. Magnified, the moth looks
completely different. Brilliant colors dance on its iridescent wing scales in a
stunning pattern. “That one is Philodoria
splendida,” Boone grins. “Splendid, no? Here,” he says, switching the
specimen for another, “take a look at this one.” It, too, is magnificent. Each
species has a unique and colorful pattern. As Boone shows me species after
species, I come to understand why Johns and the entomologists that preceded him
were so taken with them.

It might seem strange that such beautiful
animals would be ignored by science for so long, but in the world of
entomology, like other biological disciplines, bigger, more charismatic species
are the first to be described and attract more study. “For the macro
butterflies, we pretty much know what most of the species are,” says Boone.
Their smaller cousins have had to wait for their moment in the scientific
spotlight. Despite their size, they still offer a wealth of opportunity for
discoveries that might tell part of a much larger story. “There’s still a lot
of work to be done,” says Boone. “We want to know: Are they still around?
What’s going on with their populations? Is development taking away their
habitats?”

Over the past four years, Johns has started
to answer some of those questions. Using genetic sequencing techniques, he and
Kawahara are reconstructing the moths’ family tree to understand when the
micro-moths arrived in Hawai‘i, how many species there were and how many
remain. It seems the Philodoria split
from their South Pacific relatives sometime between one hundred thousand and
five million years ago—kind of a wide range—and Johns is working to better
pinpoint when.

That means Philodoria could have arrived here even before the main Hawaiian Islands
existed, “which is pretty wild,” says Johns. “It was once thought that a lot of
organisms endemic to Hawai‘i arrived on Kaua‘i about five million years ago and
then radiated along the island chain as new islands formed,” he says. But new
genetic evidence suggests that some organisms—including Philodoria, possibly—got to Hawai‘i even earlier, landing on places
like Laysan Island and Kure Atoll before they became the low islands and atolls
of the Northwestern Hawaiian Islands we know today. If Philodoria did come to Hawai‘i that long ago, studying their host
plants and habitats could give scientists a better picture of what Hawaiian
ecosystems looked like millions of years before the islands we think of as
Hawai‘i rose from the sea.

When Johns began the project, thirty species
of Philodoria had been described.
Johns has discovered more than a dozen new species, bringing the current total
to forty-four. That might not seem like much for a genus of bugs, but
considering that they might all derive from a common ancestor, Philodoria “exhibit the classic
characteristics of adaptive radiation in Hawai‘i,” says Johns. These islands
are famous for adaptive radiation, the term for when numerous species evolve
from a common ancestor. Hawai‘i’s fifty-four known honeycreepers, for example,
are thought to have evolved from a finch that arrived between four million and
seven million years ago—perhaps the world’s greatest example of adaptive
radiation among birds. The Islands’ 126 lobelia species derive from a plant
that arrived about 13 million years ago, one of the most spectacular examples
of plant radiation anywhere on Earth. Like the lobelias and honeycreepers, Philodoria “are one of the great
Hawaiian radiations—it’s just that most people haven’t heard of them yet.”

Johns believes there are more species yet to
be found. “Previous collectors probably didn’t get to plants that were
extremely rare or in really remote locations,” he says, and there are still a
lot of plants he hasn’t yet seen himself. At the same time, dozens of species
unknown to science might now be long gone. The loss of micromoths no one has
ever seen might seem like a small thing to mourn when so many species are under
threat. “To some people, caring about a little moth is a little ridiculous, but
I believe I came from this land, these plants, these animals,” says Bustamante,
who is part Native Hawaiian. It’s right there, he says, in the Kumulipo, the
ancient Hawaiian creation story. “The Kumulipo says that all the things of
nature came before us and we came from them. ... We are dependent on all those
things of nature that came before us.”

It’s an indigenous perspective that jibes
with Western science. I ask Boone why these moths matter. “They’re part of the
ecosystem,” he says matter-of-factly. “If you remove anything from an
ecosystem, you’re going to do some harm.” That might seem obvious to a
scientist, but convincing laypeople that micromoths matter is a little harder.
“If you say ‘moth,’ a lot of people’s eyes glaze over,” Johns says. “Then if
you say ‘microscopic moth that you’re never going to see,’ you get even more
glaze. But they’re part of the story of Hawai‘i. They’re part of Hawai‘i’s
biodiversity, and Hawai‘i’s biodiversity is part of Hawaiian culture.”